Step on it and it tells you how much you weigh on the moon, mars, pluto, the sun, or on the ISS. Pick a couple of your favorite weights to show at any time.

This is so you can start your diet weighing yourself on the earth but later switch to pluto
if you haven't been having any luck.

This is a tricky one, because the scale should read in kilograms,
which is a unit of mass, not weight; and mass is constant
irrespective of local gravity.

Bathroom scales actually measure force, in Newtons, and convert
that using an assumed general value of g to kilos.

On a body with a different value of g, the downforce changes,
but the mass (and inertia) are constant.